Cepaea nemoralis

Geographic Range

The northern distribution boundary of Cepaea nemoralis is in Scotland and southern Scandinavia. The range extends south to the Iberian Peninsula and Croatia in the south. Capaea nemoralis is found in the western and eastern coasts of both Ireland and the UK, Belgium, and France. The eastward distribution extends to the northwestern areas of Poland. This species was introduced in southeastern Poland, where it currently thrives. Cepaea nemoralis was introduced into North America during the nineteenth century and is currently found in Virginia, New York, Ontario, and Massachusetts. (Bellido, et al., 2002; Brussard, 1975; Cain, 1968; Chang and Emlen, 1993; Jordaens, et al., 2006; Ozgo, 2005; Richards and Murray, 1975)

Habitat

Cepaea nemoralis is found in habitats ranging from hedgerows to downland turf and from beech woods to sand dunes near the sea. This species is also found throughout grasses and herbs. A relatively small amount is found in Marram grass. Unbanded and yellow C. nemoralis are mostly found in open habitats. Colonies with a green background have a high proportion of yellow C. nemoralis. Yellow C. nemoralis can also be found in shaded areas and banded shells of this species are found in areas of hedgerows and mixed rough herbage. In areas where the type of land is discontinuous, branded C. nemoralis are found. In Southeastern Poland, where C. nemoralis has been introduced, the species is found in urban environments where it inhabits gardens, orchards, cemeteries, hedgerows and other vegetation made up of herbs. In the hot and dry months of the summer, C. nemoralis is also found in tall plants and plants with large leaves or stems. Two of these plants include goldenrod and Centaurea. During hibernation C. nemoralis are found underground on land and underwater where they can survive for 2-3 weeks. (Cain, 1968; Cameron, 2001; Chang and Emlen, 1993; Goodhart, 1962; Ozgo, 2005; Richards and Murray, 1975; Sheppard, 1951)

  • Other Habitat Features
  • urban

Physical Description

Cepaea nemoralis has a yellow, pink, or brown shell. The shell contains as many as five dark bands (each 360 degree revolution constitutes one band). The shells are made up of different layers. The outer layer (periostracum) is made up of conchiolin and the layer directly layer is much thicker and is composed of calcium carbonate. Calcium is an important component of the shell and it is an important factor that determines the shell strength. Calcium concentrations vary from 319 to 359 mg/g. The shell strength, measured in Newtons required to break it, varies from 35 to 63 N. Cepaea nemoralis shell thickness varies from 0.17 to 0.21 mm. The dry weight of the shell varies from 0.43 to 0.72 g. The shell volume measures anywhere from 2230 to 3012 cubic mm. (Cameron, 2001; Jordaens, et al., 2006; Ozgo, 2005; Richards and Murray, 1975; Richardson, 1975a; Richardson, 1975b; Sheppard, 1951; Williamson and Cameron, 1976)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    0.72 (high) g
    0.03 (high) oz
  • Range basal metabolic rate
    0.014 to 0.251 cm3.O2/g/hr
  • Average basal metabolic rate
    0.134 cm3.O2/g/hr

Development

In Europe, from 30-80 eggs (2.3-3.0 mm in diameter) are laid and hatch in 15-20 days. High temperatures and low humidity reduce the snail's activity and therefore inhibits growth rate. Cepaea nemoralis can form the peristome lip, which indicates it is an adult, in one active season. Juveniles may take to three years to develop into adults.

The color variation in the shells of Cepaea nemoralis is determined genetically by allelic series. Yellow shell alleles are recessive to pink shell alleles, and both yellow and pink shell alleles are recessive to brown shell alleles. The unbanded shell allele is dominant to banded. (Gilliland, 2005; Ozgo, 2005; Schultes, 2011)

Reproduction

Cepaea nemoralis is hermaphroditic and mates more than once. A mating partner for C. nemoralis is random, according to color, size and banding patterns. The snails can store sperm for long periods of time. Each individual C. nemoralis may produce offspring from several matings in each brood. The average number of mates per brood is two. Cross fertilization is obligatory.

The offspring of each C. nemoralis is divided into a number of broods that is produced over a period of months or even years. This makes it unlikely that the fates between different broods will mimic each other. Each brood consists of genetic contributions from one female parent and two male parents. This reduces the dependence of single parents for survival within a whole brood unit. This system of multiple mating and sperm storage protects organisms that are minimally mobile from complete fatality within a gene pool.

Courtship of C. nemoralis is elaborate. A calcareous dart is jabbed into a potential partner before mating begins. In order to prevent accidental mating between C. nemoralis and a closely related species, Cepaea hortensis, the two species have different darts. ("Gastropods", 1989; Murray, 1964)

The breeding interval of Cepaea nemoralis runs from April through October. The relative seasons are spring, summer and the beginning of the fall. The number of offspring per brood is around 23. Eggs are laid simultaneously in a dug nest in soil. The snail's foot is used to create a cavity in soil for laying eggs. The laying of the eggs can take up to three days and when complete, its foot is used again to cover the nest.

The average number of hatched young per year is 33. The eggs of one brood may survive or die as a unit; however, once they hatch, the individual's survival is not correlated to the rest of the brood. High temperatures and low humidity reduce the snail's activity and therefore inhibits growth rate and egg production. ("Gastropods", 1989; Chang and Emlen, 1993; Goodfrien, 1983; Goodhart, 1962; Greenwood, 1974; Murray, 1964; Wolda, 1967)

  • Breeding interval
    This species breeds 1 to 2 times yearly.
  • Breeding season
    Breeding season is from April to October.
  • Average number of offspring
    23
  • Range age at sexual or reproductive maturity (female)
    1 to 2 weeks
  • Range age at sexual or reproductive maturity (male)
    1 to 2 weeks

Cepaea nemoralis produces eggs at the same time and are laid in nest they dig and cover up with soil. Beyond hatching, there is no parental care. (Murray, 1964)

Lifespan/Longevity

Cepaea nemoralis may live up to six years in the wild, but this is uncommon because of predation. In captivity, they may live up to 10 years. The average lifespan of C. nemoralis is 2.3 years. The survival rates of the young greatly differs and can range anywhere from 0.3 to 0.7. However, in most cases, the rate is closer to 0.3. It depends on the region and the temperature. (Goodhart, 1962; Greenwood, 1974; Jordaens, et al., 2006)

  • Range lifespan
    Status: wild
    6 (high) years
  • Average lifespan
    Status: wild
    2.3 years
  • Range lifespan
    Status: captivity
    10 (high) years
  • Average lifespan
    Status: wild
    2.3 years

Behavior

Cepaea nemoralis has different behaviors throughout different times of the year. In the summer, the species moves to an elevated and shaded part of vegetation during the mornings. The elevation provides C. nemoralis with lower temperatures and the shade from vegetation provides protection from the sun's rays. In the spring and fall, C. nemoralis does not exhibit this climbing behavior. This is because the climates of the spring and fall are milder than that of the summer. In the spring, there is a high degree of food scarcity which leads to C. nemoralis preferring food over shelter. In the fall, however, C. nemoralis displays preference for shelter rather than food because of the relative food abundance.

Cepaea nemoralis lives amongst each other with a density range of 0.5 to 3.5 adults per square meter. The average density is 1.4 adults per square meter. Populations of any group of C. nemoralis range anywhere from 380 to 14,000 total snails. A higher population usually indicates a higher adult density (per square meter).

Capaea nemoralis, on average moves 3.018 meters per year or 0.826 cm per day. (Chang and Emlen, 1993; Goodhart, 1962; Greenwood, 1974)

Communication and Perception

Cepaea nemoralis is able to respond to painful and non-painful stimuli. During the night, C. nemoralis feels more pain. Calcium channels are involved in the regulation of neuronal functions in mollusks in a manner like vertebrates. Similar intermediary messenger systems also exist between Cepaea and rodents.

Cepaea nemoralis predominantly moves in an upwind direction. They first randomly move in any direction before following the upwind stream. The decision to move upwind is made when the odor of favored foods is detected. Interactions between C. nemoralis exist. As the number of individuals within a colony increases, there is a decline in juvenile growth rates and birth rates. Limited resources is not the explanation because even in areas of normal competition, there is still growth rate and birth rate declines. This indicates that there is either a chemical or behavioral type of communication within the species that is responsible for the declination. (Goodfrien, 1983; Kavaliers and Ossenkopp, 1991; Williamson, et al., 1976)

Food Habits

Cepaea nemoralis prefers to eat dead plant material rather than fresh. They also prefer to eat herbs rather than grasses. Adult C. nemoralis show greater selectivity in their eating habits than the juveniles, although they eat some grasses while juveniles do not. They eat Poterium sanguisorba and Leontodon hispidus. Lotus corniculatus and Urtica diocia are examples of rarely consumed greens. Cepaea nemoralis avoid vetch, shrub and grass in their diet. Remains of ants, beetles, spiders, mites, springtails and aphids are found in the diet of C. nemoralis, but these are probably the remains that were eaten along with greens and herbs.

In a colony that is as dense as 5 adults per square meter, the mean annual biomass consumed is 1.03 g per square meter. A large C. nemoralis can eat 125 mg of food per week, meaning a daily consumption rate of 59.5 mg of food per 1 g of dry tissue weight of the snail. Cepaea nemoralis relies on large lumps of food and its hydrolytic enzymes in its gut for nutrition. Vitamins A and B and some sterols are required components of C. nemoralis nutrition. Adults require sitosterol, a plant sterol. ("Gastropods", 1989; Chang and Emlen, 1993; Richardson, 1975b; Williamson and Cameron, 1976; Williamson, et al., 1976)

  • Animal Foods
  • insects
  • Plant Foods
  • leaves
  • wood, bark, or stems
  • fruit
  • flowers

Predation

Birds, mice, and rats are the most significant predators of Cepaea nemoralis. In Europe, the most common predator of C. nemoralis is song thrushes. Predators feed on snails by cracking the shells on nearby hard objects or with the use of their teeth.

Other predators of C. nemoralis include the rook, the brown rat, hedgehogs, moles, field mice, Sorex, rabbits, and maggots. Phorid flies are parasitic and consume C. nemoralis.

Anti-predator adaptations of C. nemoralis include the complexity of color and bands on shell varying with the complexity of the landscape, known as background matching. Brown shelled C. nemoralis are found in landward parts which are generally complex landscapes. Unbanded shells are found in the most pitted areas. The greatest complexity in the variation of shell colors and whether or not the shells are un/banded correlates with the amount of enclosed spaces such as pits that serve as amphitheaters for other organisms. Song Thrushes, a main predator of C. nemoralis, preys on shells that are distinguishable from the environment.

Another anti-predator adaptation of C. nemoralis is shell thickening. Thickening of the shell prevents the ability of a predator to crush the shell. It also increases the "handling time" of the snail. Increasing handling time makes C. nemoralis less energetically rewarding prey. Crushing resistance positively correlates with calcium concentration. (Cain, 1968; Cook, 2008; Currey, 1964; Goodhart, 1962; Jordaens, et al., 2006)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Phorid flies are parasitic on C. nemoralis. (Goodhart, 1962)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Cepaea nemoralis display a significant amount of polymorphism in their shells. This polymorphism has been the subject of many evolutionary studies in Europe. (Brussard, 1975)

  • Positive Impacts
  • research and education

Economic Importance for Humans: Negative

There are no known adverse affects of Cepaea nemoralis on humans.

Conservation Status

Cepaea nemoralis is listed as "least concern" in the Czech Republic. It is not specially listed by any other countries or organizations. (Jurickova, et al., 2001)

Contributors

Sami Hammoud (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, Renee Mulcrone (editor), Special Projects.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

biodegradation

helps break down and decompose dead plants and/or animals

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

delayed fertilization

a substantial delay (longer than the minimum time required for sperm to travel to the egg) takes place between copulation and fertilization, used to describe female sperm storage.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

induced ovulation

ovulation is stimulated by the act of copulation (does not occur spontaneously)

infrared/heat

(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.

internal fertilization

fertilization takes place within the female's body

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

magnetic

(as perception channel keyword). This animal has a special ability to detect the Earth's magnetic fields.

male parental care

parental care is carried out by males

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sperm-storing

mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

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